JAE LEE Seeks To Control Methane Hydrate Formation

July 16, 2009

JAE LEE Seeks To Control Methane Hydrate Formation

Methane hydrate is a substance consisting of molecules of methane encased in molecules of water. Naturally occurring deposits of the ice-like substance have been located in Polar Regions and on the continental shelves of the world’s oceans. They represent a potentially huge untapped energy source since the deposits may contain more organic carbon than all the world's coal, oil, and non-hydrate natural gas combined, according to the U.S. Geological Survey.

Dr. Jae Lee, Associate Professor of Chemical Engineering in The Grove School of Engineering at The City College of New York, is investigating methods for controlling methane hydrate formation. With a three-year, $304,120 grant from the National Science Foundation, he is studying techniques to accelerate and to retard its formation in order to achieve two divergent goals related to energy storage and transportation. Dr. Alexander Couzis, Professor of Chemical Engineering in The Grove School, and Dr. Camille Jones, Assistant Professor of Chemistry at Hamilton College, are his co-investigators.

Storing methane in hydrate, or solid, form can potentially be a safer and more economical alternative to compressed natural gas (CNG) or liquefied natural gas (LNG), he explains. Not only does the slow release of the gas reduce the risk of explosion, but large quantities can be kept under atmospheric pressure in that form.

However, current methods for converting methane from gas to hydrate form are hindered by a slow reaction time that Professor Lee wants to accelerate. He is investigating injecting minute quantities of surface-active agents, i.e. surfactants such as detergent, into the molecule to speed up the process.

“If we inject around 200 parts per million of surfactant agent into the molecules, their shape and particle size changes dramatically so that gas can grow into hydrate crystal form,” he notes. “The fundamental problem we are investigating is under what mechanism surfactants accelerate the reaction rate. Once you understand that, you can synthesize or make better materials for gas hydrate formation.”

Another problem being investigated in Professor Lee’s lab is how to reduce the formation of methane hydrate plugs within crude oil pipelines, which has plagued the petroleum industry since the 1930s. “To get rid of hydrate plugs, people are using polymer inhibitors. They get absorbed in the hydrate surface and block the growth of hydrate particles,” he explains.

Professor Lee sees potential applications for the techniques he is developing in carbon dioxide sequestration, i.e. the capture of carbon dioxide that would otherwise be released into the atmosphere and contribute to global warming. By converting carbon dioxide to hydrate form, it could be safely stored in the ocean at depths of 3,000 meters or more, he adds. It might be possible in the future to swap sequestered carbon dioxide for recovered naturally occurring methane hydrate.